May 1, 2024

New England’s electricity use to increase steadily over next decade, according to 2024 CELT Report

A new report from ISO New England projects regional electricity consumption will increase by about 17% over the next decade, driven primarily by the accelerating electrification of heating systems and transportation.

Load forecasters at the ISO examined expected economic growth, historical weather patterns, projected adoption of technology like distributed solar photovoltaics (PV), electric vehicles (EVs) and air-source heat pumps, and state-level carbon reduction goals to develop the 2024-2033 Forecast Report of Capacity, Energy, Loads, and Transmission (CELT Report), which serves as a foundational resource for the ISO’s system planning and reliability studies.

Components of the report include:

A long-term forecast for energy consumption and peak demand, which accounts for the impacts of electrification, energy efficiency (EE), and behind-the-meter (BTM) PV generation
The potential output of resources participating in the Forward Capacity Market (FCM), as well as the total generating capability of resources in the region
A breakdown of the region’s generators by fuel/unit classification
A link to the listing of  transmission projects proposed, planned, and under construction

Changes in regional electricity use since 1995

Net annual energy use in New England grew steadily between 1995 and 2005, driven primarily by increased economic growth and the use of air conditioning. Since 2005, net annual energy use has trended downward mainly due to an increase in energy efficiency from advanced cooling and heating technologies, energy-efficient appliances and lighting, and the increased prevalence of BTM solar generation.

However, ISO New England is predicting that trend will reverse in the next decade. The ISO is forecasting steady growth in net annual energy use as state policy goals for carbon emissions reductions drive the increased electrification of heating systems and transportation in the region.

Improved input assumptions and methodology

The ISO’s innovative load forecasters continually refine their methods and assumptions to keep pace with emerging trends.

Updates since the 2023 CELT Report include capturing the effect of new managed charging programs, which incentivize consumers to charge personal electric vehicles outside of peak demand hours.

ISO New England also continues to develop methods to better reflect the partial electrification of building heating, which assumes consumers will also use a non-electric, backup heating source during very cold weather. These improvements will provide a more accurate picture of how consumers use electric heat pumps, since these devices often supplement existing oil furnaces or woodstoves instead of replacing them.

Each year, the ISO assesses the accuracy of last year’s predictions and modifies inputs accordingly. Over the past decade, the ISO has observed a decoupling of economic growth and demand for electricity; in recent years, this led energy models to over-forecast. As a result of this benchmarking, 2024’s 10-year forecast curves for annual energy are slightly lower than those in the 2023 report, driven partly by a more nuanced approach to developing economic model inputs.

Victoria Rojo, lead data scientist on the ISO’s Load Forecasting team, talks about the CELT Report in this ISO Minute video.

New England electricity projections for 2024 to 2033

Results of the ISO’s EE forecast and solar photovoltaic (PV) forecast are applied to the gross long-term forecast to develop a net long-term forecast. The net forecast represents actual energy to be served, since EE and BTM PV reduce the amount of electricity consumers draw from the bulk power system.

Overall electricity use in New England 

Total Annual Use (GWh)	2024	2033
Net Forecast	119,179	140,001

Net annual energy use is expected to grow by 1.8% annually over the 10-year period.
Energy efficiency programs participating in the region’s wholesale electricity markets are projected to reduce electricity use by 10,618 gigawatt-hours (GWh) this year and 11,210 GWh in 2033.
BTM PV is projected to reduce consumption of grid electricity by 5,444 GWh this year, rising to 9,975 GWh in 2033.
EVs are expected to account for 15,182 GWh of energy use in 2033, while heating electrification is expected to account for 7,996 GWh that year.

Seasonal peak demand

Peak demand is a measure of the highest amount of electricity used in a single hour, and the CELT Report includes forecasts for both summer and winter peaks. Traditionally, the expected annual peak in New England occurs during the summer. ISO New England analysts use historical data on typical peak weather conditions to develop the 50/50 forecast, meaning there is a 50% chance that peak demand will be above or below the forecast. By 2033, ISO New England predicts the winter 50/50 net peak will nearly match the summer 50/50 net peak as the electrification of heating accelerates.

The 90/10 forecast—which reflects hotter, more humid peak conditions in the summer and colder temperatures in the winter—means there is a 10% chance that peak demand will be higher than the forecast.

Summer Peak Demand (MW)	2024	2033
50/50 Net Forecast	24,553	27,052
90/10 Net Forecast	26,383	29,007

Under typical summer weather conditions, net peak demand is expected to rise at an annual rate of 1%. For hotter weather, the net peak is expected to rise slightly less than 1% annually.
The net forecast includes 50/50 summer peak demand reductions from BTM PV of 1,097 megawatts (MW) this year, rising to 1,284 MW in summer 2033.
EE is expected to reduce 50/50 summer peak demand by 1,775 MW this year, and by 2,023 MW in 2033.
Transportation electrification is expected to contribute 2,334 MW to 50/50 summer peak demand in 2033.

Winter Peak Demand (MW)	2024/2025	2033/2034
50/50 Net Forecast	20,308	26,768
90/10 Net Forecast	21,089	28,270

Under typical winter conditions, net peak demand is expected to rise by an average of 3.1% annually through the winter of 2033/2034. For colder weather, the net peak is expected to increase by 3.3% annually.
Transportation electrification is forecast to contribute 3,348 MW to the 50/50 winter peak and 3,440 MW to the 90/10 winter peak in 2033/2034.
Heating electrification is projected to contribute 3,604 MW to the 50/50 winter peak and 4,356 MW to the 90/10 winter peak in 2033/2034.
BTM PV does not reduce winter peak demand, because the peak typically occurs after sunset.